1. Field of the Invention
This invention pertains to the general field of floating structures and, in particular, to floating platforms of modular construction.
2. Description of the Prior Art
As the population of the world increases and large cities expand over crowded shores, floating platforms have become an acceptable location for strategic and commercial activities. In my copending application I described a concept for a floating airport capable of accommodating a large number of aircraft as an alternative to civil and military aviation's reliance on thousands of airports strategically located on land around the world and on airplane carriers at sea. Modern airports have become mazes of runways, hangars and terminals used to move millions of people and tons of cargo material every day. Problems of congestion, security, safety, noise, pollution, and distance from residential areas all contribute to sometime contradictory solutions for urban airports. The high traffic volume of a modern metropolis requires sufficient runways to take care of very frequent landings and take-offs. Therefore, even smaller airports have multiple runways spread out over several square kilometers of premium land. In addition, since the optimal direction for both take-off and landing maneuvers changes with the direction of the prevailing wind, multiple sets of intersecting runways are usually provided, creating a system of paved roads many kilometers long in all directions. This causes airplanes to taxi over long distances before and after each flight, wasting fuel and passenger time and contributing to environmental pollution.
One other aspect of urban airports is that they need to be accessible and yet be far enough from residential areas to avoid unacceptable levels of noise. As a result, they are either placed tens of kilometers from town or the flight patterns are adjusted to avoid maneuvers directly over populated areas. The former case complicates the logistics of travel for the average passenger who has to face a relatively time-consuming journey to and from the airport in addition to flight time. The flight pattern constraints are particularly significant in bad weather because they force the performance of suboptimal landings as a result of the restrictions, increasing the danger of mid-air collisions and of problems on impact.
The invention disclosed in my copending application is directed at a floating-airport concept that solves many of these problems. Various inventions have been described in the prior art to address particular air navigation needs. For example, U.S. Pat. No. 1,513,591 to Dorr et al. (1924) discloses the idea of a floating hangar for airships based on a single-hull design. The invention first introduces the concept of utilizing the unitary construction of a ship's hull to provide the buoyancy required for supporting the shed above water. Flood chambers are used to raise or lower the bottom of the hanger to the desired elevation with respect to water level. The structure is provided with a single-point anchoring system that permits the rotation of the shed to face the wind. Although the purpose of this feature is not expressly stated, it was presumedly intended for stability and for facilitating the process of taking airships aboard.
U.S. Pat. No. 1,854,336 to King (1932) describes a floating landing strip, seemingly a precursor to modern airplane carriers. The invention relates to a runway supported by multiple submergible pontoons that permit the raising or lowering of the unit. The structure is propelled and intended for navigation and anchoring on large bodies of water.
In U.S. Pat. No. 1,753,399 (1930), Blair describes an ocean-going aircraft-carrying structure with a system of hulls designed to reduce the impact of wave motion. The bulk of the volume of the hulls is under the water level, so that the impact of surface-water motion is minimized.
In U.S. Pat. No. 2,133,721 (1938), Seidman describes an airplane terminal having a submersed rotating platform for retrieving and releasing aquatic airplanes. The invention is directed at means for coordinating passenger and cargo traffic between land and arriving or departing hydroplanes.
U.S. Pat. No. 2,342,773 to Wellman (1944) discloses a landing platform formed on the surface of a body of water adjacent to a ship. The platform is made with material carried by the ship in rolled form and reeled offboard over the water to create a landing strip when needed. Inflatable compartments are provided for buoyancy.
U.S. Pat. No. 3,191,566 to Wilken et al. (1965) shows a waterborne craft for airplanes capable of attaining the normal speed of a plane during landing. As a result of this feature, which is achieved with hydrofoil technology, the vessel is able to provide a relatively stationary target for landing airplanes and to enhance the take-off air velocity of departing aircraft.
Finally, U.S. Pat. No. 4,744,529 to Clarke (1988) teaches a system for recovering disabled airplanes in water. It consists of a large net having sufficient size to accommodate an aircraft during landing in water and comprises floats for supporting the net and craft. The system is designed for emergency operation in conjunction with a tug boat.
None of the concepts described by the prior art had addressed the particular modern-airport problems mentioned above, or suggested solutions to them. Therefore, the floating-airport concept of my copending application provides a useful new approach to airports that optimizes space utilization, safety, convenience, and efficiency of operation.
During the course of refining the design of such a floating-airport structure, I have developed a method and details of construction that I found to be generally applicable to any floating platform. This could be, for example, a residential or office complex, a floating recreational platform, a waste disposal plant, a chemical manufacturing facility, an oil refinery, a transhipping dock or warehouse, or any other industrial, commercial, scientific, or military off-shore facility. This disclosure is directed at such details and a novel construction approach generally applicable to off-shore floating platforms.